Over the past decade, disposable diapers, which include fluid-absorbent interior pads positioned between fluid-permeable top cover sheets and fluid-impermeable bottom cover sheets, have become increasingly popular. These disposable diapers are fabricated and sold in various shapes, sizes and constructions.
More recently, disposable diapers known in the trade as "elastic leg" disposable diapers have been introduced and are gaining popularity. These disposable diapers are preferably of generally hour-glass configuration including a central crotch-fitting area and outer waist-fitting areas and have elastic strips secured along the outside longitudinal edges of the crotch area of the disposable diapers for forming extendible side portions along the crotch area of the diaper for elastic compliance to the legs of the wearer, such as has heretofore been available with waterproof panties utilized in diapering infants. Examples of commercial forms of such elastic leg diapers may be seen in The Procter & Gamble Company's U.S. Pat. No. 3,860,003 and Kimberly-Clark Corporation's U.S. Pat. No. 4,050,462.
Although the elastic leg disposable diapers commercialized under each of these two prior art patents are apparently successful in the marketplace, the diapers of these two prior art patents suffer from certain disadvantages relating to the manner in which the elastic strips are secured within the longitudinal edges of the diaper which result in structural deficiencies and an expensive and complicated procedure of inserting such elastic strips.
Although the Procter & Gamble U.S. Pat. No. 3,860,003 does not fully and clearly disclose the process utilized in inserting the elastic strips within the longitudinal edges of the disposable diaper, its subsequent U.S. Pat. No. 4,081,301 clearly discloses such process. As may be seen in this Procter & Gamble U.S. Pat. No. 4,081,301 and in the Kimberly-Clark U.S. Pat. No. 4,050,462, both of these elastic leg disposable diaper products involve the insertion of the elastic strips within the longitudinal edges of the disposable diaper being manufactured in serially-interconnected form by a process in which adhesive is intermittently applied to spaced-apart portions or lengths of continuous strips of elastic and the elastic strips are continuously stretched and secured within the longitudinal edges of the disposable diapers so that the portions of the elastic strips having adhesive thereon are secured within the crotch area of the diaper and the lengths of the elastic strips without adhesive thereon are positioned within the longitudinal edges of the outer waist areas of the diaper. With this construction, when the disposable diapers are cut apart into individual diapers and the elastic strips are cut, the portions of the elastic strips which are unsecured within the waist-fitting portions of the diaper will snap within the diaper leaving loose ends therein and the portion of lengths of the elastic strips secured within the crotch area of the diaper will gather such area forming extendible side portions.
As a result of the above manufacturing process, the snapping in of the loose or unsecured ends of the elastic strips at the outer waist-fitting areas of the diaper sometimes results in damage to the diaper and leaves open passages through the transverse edges of the diaper which may be susceptible to moisture leaks, etc. Also, this prior manufacturing process requires complicated and expensive equipment, such as that disclosed in the above-identified Procter & Gamble U.S. Pat. No. 4,081,301.